1. Field of the Invention
The present invention relates to a dielectric film and a dielectric element such as a thin-film capacitor, which includes the dielectric film.
2. Description of the Related Art
With multi-functionalization of electronic apparatuses, various functions are desired to be added to electronic circuit boards contained in electronic apparatuses. Therefore, the number of electronic components mounted on an electronic circuit board tends increase. Thus, there is strong demand for improving the mounting density of electronic components.
One of the proposed answers to the demand is to embed electronic components in an electronic circuit board. One of the many electronic components mounted on an electronic circuit board is a usual laminated ceramic capacitor. However, when the laminated ceramic capacitor is embedded in an electronic circuit board, the thickness of the laminated ceramic capacitor and brittleness as a ceramic property cause the problem of producing, by the stress generated in an embedding process, cracks in the laminated ceramic capacitor or deformation in a portion of the electronic circuit board where the laminated ceramic capacitor is embedded.
It is difficult to resolve the problem even by a usual laminated ceramic capacitor having a very small shape. Therefore, a lower-profile capacitor than the laminated ceramic capacitor is required as a capacitor for embedding in an electronic circuit board. A thin-film capacitor is generally known as a low-profile capacitor.
Thin-film capacitors are widely used for decoupling capacitors as small high-performance electronic components. Therefore, in addition to high dielectric constant and high breakdown voltage, a small change in capacitance with temperature over a wide temperature range of −55° C. to 125° C. in an operating atmosphere is required because the temperature is increased by heat generated from electronic components with increasing mounting density.
(Ba1-xCax)z(Ti1-yZry)O3 (hereinafter abbreviated as “BCTZ”) is generally known as a material having a high dielectric constant (Japanese Unexamined Patent Application Publication No. 2005-22890).
Japanese Unexamined Patent Application Publication No. 2000-173349 discloses a technique for the dielectric constant and breakdown voltage of a BCTZ thin film. However, a change in capacitance with temperature is not described, and a manufacturing method is limited.